Sir Alex Ferguson's side confirmed on Wednesday night they had agreed a fee, thought to be £23m, for the Dutch striker who is expected to undergo a medical on Thursday and finalise terms.

"He is at Manchester United, unfortunately for us. The transfer was finalised in the afternoon," said Wenger while working for the French TV station TF1.

"It's never great to lose players of that quality but he only had a year contract so we do not have a choice.

"We have already recruited since we bought [Olivier] Giroud and [Lukas] Podolski who originally were intended to offset the departure of van Persie," he concluded.

Thomas Vermaelen maintains Arsenal must put van Persie's departure behind them and focus on mounting a sustained assault on the Barclays Premier League. "He was fantastic for us in the last year, scored lots of goals and I am disappointed he is going, but we have to focus on the next season with Arsenal," Vermaelen told Sky Sports News.

"We have to fight and I am confident we have a squad to win something. We start Saturday and this is all clear now, Robin is leaving and we have to move on."